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Improved paged attn prefix caching #1434

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Merged
merged 2 commits into from
Jun 5, 2025
Merged

Improved paged attn prefix caching #1434

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5c4e3f3
Improved paged attn prefix caching
EricLBuehler Jun 5, 2025
597f41e
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EricLBuehler Jun 5, 2025
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4 changes: 4 additions & 0 deletions mistralrs-core/src/paged_attention/block_engine.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,10 @@ impl LogicalTokenBlock {
self.tokens.pop();
self.num_tokens -= 1;
}

pub fn toks(&self) -> &[usize] {
&self.tokens
}
}

impl Hash for LogicalTokenBlock {
Expand Down
62 changes: 29 additions & 33 deletions mistralrs-core/src/prefix_cacher.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@

use crate::{
get_mut_arcmutex,
paged_attention::{BlockEngine, BlockEngineSequence, LogicalTokenBlock, PhysicalTokenBlock},
paged_attention::{BlockEngine, LogicalTokenBlock, PhysicalTokenBlock},
pipeline::KvCache,
sequence::{self, Sequence},
};
Expand Down Expand Up @@ -116,36 +116,27 @@
return;
}

if let Some(block_engine) = &self.block_engine {
let logical_token_blocks = seq.logical_token_blocks();
let block_engine = get_mut_arcmutex!(block_engine);
let block_table = &block_engine.block_tables[seq.id()];
let hashed_logical_blocks = hash_logical_blocks(logical_token_blocks);

if !self.block_caches.contains_key(&hashed_logical_blocks) {
for block in block_table {
let id = block.deref_mut().block_id;
for BlockCacheElement {
physical_blocks, ..
} in self.block_caches.values()
{
if physical_blocks.iter().any(|x| x.deref_mut().block_id == id) {
return;
}
}

block.deref_mut().increment_refcount();
}

self.block_caches.insert(
hashed_logical_blocks,
BlockCacheElement {
logical_blocks: logical_token_blocks.to_vec(),
physical_blocks: block_table.clone(),
image_hashes: seq.image_hashes().map(|x| x.to_vec()),
},
);
}
if let Some(_block_engine) = &self.block_engine {

Check failure on line 119 in mistralrs-core/src/prefix_cacher.rs

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unneeded `return` statement
return;
// let logical_token_blocks = seq.logical_token_blocks();
// let block_engine = get_mut_arcmutex!(block_engine);
// let block_table = &block_engine.block_tables[seq.id()];
// let hashed_logical_blocks = hash_logical_blocks(logical_token_blocks);

// if !self.block_caches.contains_key(&hashed_logical_blocks) {
// for block in block_table {
// block.deref_mut().increment_refcount();
// }

// self.block_caches.insert(
// hashed_logical_blocks,
// BlockCacheElement {
// logical_blocks: logical_token_blocks.to_vec(),
// physical_blocks: block_table.clone(),
// image_hashes: seq.image_hashes().map(|x| x.to_vec()),
// },
// );
// }
} else {
let cache = seq.normal_cache().to_vec();

Expand Down Expand Up @@ -338,8 +329,13 @@

// If the last reused block is full, reserve an extra empty block for new tokens
let new_toks = toks[match_len..].to_vec();
for _ in 0..new_toks.len().div_ceil(block_size) {
logical_prefix.push(LogicalTokenBlock::new(block_size));
logical_prefix.push(LogicalTokenBlock::new(block_size));
for tok in &new_toks {
sequence::util_append_token_to_blocks(
*tok as usize,
&mut logical_prefix,
block_size,
);
}
if logical_prefix.last().is_some_and(|last| last.is_full()) {
logical_prefix.push(LogicalTokenBlock::new(block_size));
Expand Down
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